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| + | /* |
| + | * volume_id - reads filesystem label and uuid |
| + | * |
| + | * Copyright (C) 2004 Kay Sievers <[email protected]> |
| + | * Copyright (C) 2009 Vladimir Dronnikov <[email protected]> |
| + | * |
| + | * This library is free software; you can redistribute it and/or |
| + | * modify it under the terms of the GNU Lesser General Public |
| + | * License as published by the Free Software Foundation; either |
| + | * version 2.1 of the License, or (at your option) any later version. |
| + | * |
| + | * This library is distributed in the hope that it will be useful, |
| + | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| + | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| + | * Lesser General Public License for more details. |
| + | * |
| + | * You should have received a copy of the GNU Lesser General Public |
| + | * License along with this library; if not, write to the Free Software |
| + | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| + | */ |
| + | |
| + | #include "volume_id_internal.h" |
| + | |
| + | #define BTRFS_UUID_SIZE 16 |
| + | #define BTRFS_LABEL_SIZE 256 |
| + | #define BTRFS_CSUM_SIZE 32 |
| + | #define BTRFS_FSID_SIZE 16 |
| + | |
| + | #define BTRFS_MAGIC "_BHRfS_M" |
| + | |
| + | struct btrfs_dev_item { |
| + | uint64_t devid; |
| + | uint64_t total_bytes; |
| + | uint64_t bytes_used; |
| + | uint32_t io_align; |
| + | uint32_t io_width; |
| + | uint32_t sector_size; |
| + | uint64_t type; |
| + | uint64_t generation; |
| + | uint64_t start_offset; |
| + | uint32_t dev_group; |
| + | uint8_t seek_speed; |
| + | uint8_t bandwidth; |
| + | uint8_t uuid[BTRFS_UUID_SIZE]; |
| + | uint8_t fsid[BTRFS_UUID_SIZE]; |
| + | } PACKED; |
| + | |
| + | struct btrfs_super_block { |
| + | uint8_t csum[BTRFS_CSUM_SIZE]; |
| + | uint8_t fsid[BTRFS_FSID_SIZE]; // UUID |
| + | uint64_t bytenr; |
| + | uint64_t flags; |
| + | uint8_t magic[8]; |
| + | uint64_t generation; |
| + | uint64_t root; |
| + | uint64_t chunk_root; |
| + | uint64_t log_root; |
| + | uint64_t log_root_transid; |
| + | uint64_t total_bytes; |
| + | uint64_t bytes_used; |
| + | uint64_t root_dir_objectid; |
| + | uint64_t num_devices; |
| + | uint32_t sectorsize; |
| + | uint32_t nodesize; |
| + | uint32_t leafsize; |
| + | uint32_t stripesize; |
| + | uint32_t sys_chunk_array_size; |
| + | uint64_t chunk_root_generation; |
| + | uint64_t compat_flags; |
| + | uint64_t compat_ro_flags; |
| + | uint64_t incompat_flags; |
| + | uint16_t csum_type; |
| + | uint8_t root_level; |
| + | uint8_t chunk_root_level; |
| + | uint8_t log_root_level; |
| + | struct btrfs_dev_item dev_item; |
| + | uint8_t label[BTRFS_LABEL_SIZE]; // LABEL |
| + | // ... |
| + | } PACKED; |
| + | |
| + | int volume_id_probe_btrfs(struct volume_id *id /*,uint64_t off*/) |
| + | { |
| + | #define off ((uint64_t) (64 * 1024)) |
| + | struct btrfs_super_block *sb; |
| + | |
| + | dbg("btrfs: probing at offset 0x%llx", (unsigned long long) off); |
| + | |
| + | sb = volume_id_get_buffer(id, off, sizeof(*sb)); |
| + | if (sb == NULL) |
| + | return -1; |
| + | |
| + | if (memcmp(sb->magic, BTRFS_MAGIC, 8) != 0) |
| + | return -1; |
| + | |
| + | // N.B.: btrfs supports 256-byte labels |
| + | volume_id_set_label_string(id, sb->label, VOLUME_ID_LABEL_SIZE); |
| + | volume_id_set_uuid(id, sb->fsid, UUID_DCE); |
| + | |
| + | return 0; |
| + | } |